Summers can get hot, and as anyone who's ever moved to a crowded city can tell you, it's expensive to buy and keep an air conditioner. If you've bought a cheap air conditioner and want a little more fine tuning without shelling out more than $200, there's hope yet.

A simple plug-in called the ThinkEco SmartAC Modlet can give your "dumb" AC smart functionality: scheduling, temperature controls, and Wi-Fi connected controls. The Modlet comes in packages ranging from $80 for the Modlet alone to $140 for a Modlet and a remote.

The great thing about having "smart" capabilities in an air conditioner is that you get finer, more automated control over your room temperature. If the temperature drops too low, you won't have to shut the AC off manually — the Modlet will cut the power for you. If you're coming work and want a cool home when you get back, you can schedule the AC to turn on before you get back.

You really only need the Wi-Fi-capable Modlet at $80 for a complete setup — if you want the convenience or you don't have a smartphone, the remote is there for an extra $60.

And if you're in the right place, you can get a Modlet for free.

Con Edison, a major electric company in the New York City area, is running a Smart AC program where the cost of the Modlet is completely subsidized. You just have to enter your details and and the company will send you a unit.

The catch is that you have to keep your AC running for at least four hours during a single "demand response event," during which the company will collect data from your Modlet to analyze electricity use.

To get that data, the company needs you to keep the Modlet to run on an uninterrupted Wi-Fi connection for at least four hours during one of those events. The fine print is here and worth reading through.

If your connection drops during any of those events, it doesn't count. And if you don't participate at all, the company charges you $90 for the cost of the device (if you don't return it after they send you a notice). Strict, but that's what "free" costs.

If you're a Massachusetts, Rhode Island, or Upstate New York resident, you can sign up for the National Grid's coolControl program, which will also give you your choice of a Modlet or a smart thermostat for free. The company similarly requires you to participate in demand response events — the full terms are written out here.